Question

найдите f'(П), если f(х)=cos х/х

Answer 1

$f(x)=frac{cosx}{x}$

$f'(x)=frac{-xsinx-cosx}{x^2}\ f'(pi)=frac{-pi sinpi-cospi}{pi^2}=frac{0+1}{pi^2}=frac{1}{pi^2}$